Why do water droplets form on the walls of a glass tumbler when cold water is poured in?

When cold water is poured into a glass tumbler, it cools down the air inside the tumbler. This cooling effect causes the water vapor present in the air to condense into tiny water droplets on the walls of the tumbler. This phenomenon is known as condensation.

Explanation:
1. Temperature Difference: When cold water is poured into the glass tumbler, it lowers the temperature of the air inside the tumbler. The temperature difference between the cold water and the surrounding air causes the air inside the tumbler to cool down.

2. Cooling of Air: As the air cools down, its ability to hold moisture decreases. The cold air inside the tumbler cannot retain the same amount of water vapor as warm air. This leads to the excess moisture in the air condensing into liquid water droplets.

3. Formation of Water Droplets: The water vapor in the air inside the tumbler comes into contact with the cool surface of the glass walls. The cool surface acts as a condensation nucleus, providing a surface for the water vapor to condense upon. As a result, tiny water droplets form on the glass walls.

4. Visible Condensation: The condensation of water vapor onto the glass walls becomes visible as water droplets due to their larger size and accumulation. This gives the appearance of water droplets forming on the walls of the glass tumbler.

5. Humidity: The humidity of the surrounding air also plays a role in the amount of condensation that occurs. Higher humidity levels provide more moisture in the air, increasing the chances of water vapor condensing on the glass walls.

Overall, the formation of water droplets on the walls of a glass tumbler when cold water is poured in is a result of the cooling effect causing the water vapor in the air to condense into liquid water droplets on the cool glass surface.

That is condensation